Inclosed fused switch



July 16, 1929. `J. sAcHs i l INCLOSED FUSED SWITCH Filed Aug. 7, 1923 2 Sheets-Sheet 2` Patented July 16, 1929.

UNITED STATESI J'OSPH SACHS. 0F WEST HARTFORD, CONNECTICUT.

INCLOSED FUSED SWITCH.

Application filed August 7, 1923. Serial No. 656,182.

This invention is an improved inclosed switch ordinarily a fused switch, suitable for use as a service entrance switch as well as in other relations: where it is desired to allow the customer or user to have access to the fuse or fuses without submitting him to the risk of accidental contact with live parts, ornif desired, without giving him an opportunity to take unmetered current. The general object is to attain thisl principal result in a practical way, as well as other results hereinafter disclosed, 1n a switch-box of smaller size and weight and lower cost of manufac-` ture than hashitherto been considered possible within the limitations imposed by standard requirements for inelosedswitches of this class.

In my copendingapplication for inclosed fused switch, Serial No. 528,934 tiled Jan. 13, i922, I have disclosed an inclosed fused switch having an openable cover normally preventing access to the switch proper and having an additional cover means normally preventing access to the fuse and operable independently of the switch covei, the saidv means having a portion which is movable laterally so as to obstruct. the switch closing movement of the switch handle whenever the fuse cover means is in position to permitaccess to the fuses: and as disclosed iu the said application, the handle is so constructed as to engage a part'of the fuse cover means other than the said laterally projectible poi'- tion thereof for preventing the movement of the said means to access permitting position when the handle is in switch closing position. A, more specific object of the present invention is to provide a construction of the type described wherein the parts are so arranged that the laterally movable portion of the fuse cover means is directly. obstructed by the part of the handle a-t the side of the box for thereby preventing the movement of the fuse cover means to access permittingr position.

A further object of the invention is to provide a device of the class described having a novel and improved relationship between the switch cover and the fuse cover means whereby the `fuse cover means is necessarily moved to an open position whenever the switch cover is opened.

A still further .object of the invention is to provide various novel details of construction for the switch cover means.

Other objects of the invention will be apparent from the following specification and claims. i

The drawings illustrate one form of the invention as applied to -a switch .for a fourwire circuit-,but Without intending to limit the invention to this form or to any particular kind of circuit. In the drawings, Fig. 1 is a perspective view of the said inclosed fuse with the cover closed and the circuit closed;

Figure 2, asimilar view with the circuit openandthe fuse section of the cover open;

Figure 3, the same box withbothl cover sections open and with the inspection flap open; Figure 4, a perspective of the-switch-block carrying the fuses and switching elements re-` moved from the box;

Figure 5, an elevation of the box in its closed position;

Figure 6, a cross section of Figure 5 on line VI-VI; and

Figure 7, a cross section on line VII-VIIl of Figure 6.

The, inclosed switch shown in these figures comprisesl a box,- the body of which is of folded sheet metal, with a back 1 and side walls 2 and 2, and provided with knock-out or equivalent openings for the connection of wire conduits or other switch-box appurtenances. as usual. This body is intended to be secured in a vertical position, on a building wall, so that the external operating handle presently referred to is located on one side of it, being shown on the right hand side. Such expressions as vertical, horizontal, lateral and the like will be used With-the understanding that the device is normally secured in a vertical position as described but itwill nevertheless be understood that I do not thereby limit myself to the location of the device in any one position.

The switch mechanism within the box comprises o'ne or more movable switchingelements and the appropriate contact clips and binding screws therefor and one or more corresponding fuses, all of which are so arranged that the fuses arein one part of the box and the switch parts and particularly the live or service side contacts and connections are in another, thereby permitting'the closure means o f the box to beorganized so that the exposure of the fuses will not aord access to switch parts which are on the service side and hence alive evenwhen the switch is open.

This arrangement is produced with a special economy'of space and material by locatmechanism in a position in the box removed u from the back wall, and mounting the partson opposite or different faces of said support. In the present case', the said support is a base block 3, preferably, but not necesarily,made of one piece of insulating material, and mountedon two or more brackets 4.- formed on or secured t-ol opposite side walls of the box body and near the open side or rim thereof and preferably about midway between the two end or top and bottom walls. The switching elements or connector blades 5 are hinged to the contact clips 6 secured to lthe inner side of the base 3 and are adapted to close the circuit by engaging the rupturecontac-t clips 7 secured to the same side of the base. These clips are intended to be connected by appropriate binding screws or wire-clamping means 8 to the incoming servicerwires an these clips and wire connections are therefore live parts when the switch is open; The switching-element and its appurtenant parts 'may be of any appropriate 'design and have any desired mode of operation. The screws which hold the hinge clips 6 to the inner face of the base extend through the lattei' and carry the current to the correspondingfusereceiving terminals 9 which are mounted on the outer side of the base. The complementary fuse terminals 10 are secured to the same side of the base and associated with appropriate wire-connecting means or binding screws 11 for connection to the outgoing or load wires. The incoming and outgoing wire connecting means are thus situated at opposite ends of the base. When the switching elements 5 are closed, the circuit is through the live contacts 7, the switching elements, the

i clips 6, fuse clips' 9, fuses and fuse clips 10 to the wire connections 11. When the Acircuit is opened the fuse terminals and the wire connections 11 are dead. Cartridge fuses F are illustrated but it will be understood that they may be substituted by screw plug or other fuses, if desired by the obvious modification of the clips. One fuse is assignedv to each switching element, and directl in front l' of it, and the base is provided wit insulatingbarriers between the lfuses and switch blades as more plainly shown in Fig. 4.

The switching elements 5 are conjointly operated by` connection, by their insulating hooks 12, with the interior clank 13 'of the switch-operating means. Inthe )resent case this means comprises a round rod journalled in holes in the opposite side walls of the box and bent to form the craiiltl 13 within the box and bent again outside the box to form a crank arm 14 with a laterally extended handle 15. It is organized in the box so'as to have little or no axial movement or end play and it is so related with reference to the switch elements or blades 5 that when it has been rotated to close the circuit, the outside crank arm 14 is then in the position indicated ini Figs. 1 and (3, extending forwardly or transverse to the plane of the back walfl of the box. It will be observed that the crank arm and handle of the operating means are located entirely at the side of the box adjacent the wall 2 thereof.

. The box is provided with an openable front cover which serves when closed to prevent access to the switch or switches while permitting access to the fuse contacts. lVhen the switches are located at the rear of a base such as 3 which extends substantially entirely :icrossthe front ofthe box the switch cover -inay be arranged to extend over only the end portion of the box which is not occupied by the base 3. I have shown such a cover at 17. rl `he character ot the opening movement of the cover 17 can be varied but I prefer to mount the cover for pivotal movement. As illustrated it is pivotally mounted by means of a hinge 18 for movement about a vertical axis.

In addition to the openable cover for the switches I provide a front cover means which .normally serves to prevent access to the fuse contacts and which iS movable independently of the aforesaid switch cover to permit such access. In accordance with one phase of the invention the said cover means includes a laterally movable portion which, when the coverfineans is in the position for permitting access to the fuses, is located in a projecting position at one ,side of the box and in the path of the movement of the handle part 14. In obtainingr access to the fuse contacts the normal procedure is to first move the switch handle to open the switches and to then more the cover means for the fuses to expose the fuses. A s already stated, whenever the said cover means is in access permitting position 4the said laterally movable portion thereof is located in the path of movement of the handle and therefore serves to prevent movement of the handle to switch closing position. Furthermore the arrangement' is such that the handle when in switch closing position vor, in fact, when in any position other than the po- .sition corresponding to the fully open position of the switches, directly obstructs the vmovement of the said laterally movable portion of the fuse cover means so as to thereby prevent movementot the said means to access permit-ting position. I

The details of construction of the .fuse cover means may be widely varied but. I have illustrated a fuse cover means which comprises a sidewise opening cover. lVhen a sidewise opening cover is provided the said cover has a portion which partakes directly of the sidewise movement so as to projectv or belloeated in the path of movement of the said side part of the handle for the purposes already set fort-h. Different types of sidewise movement may be provided but I have part of the present invention.

illustrated a cover constructed and arranged for a sidewise pivotal movement.

The fuse cover 16 is shown as being hinged to the box body on that side which is adjacent the path of the side handle crank 14 and correlated therewith so that the cratikarm 1st obstrncts opening of the cover when in its forward or' circuit-closing position, just referred to. In this way, the cover cannot be opened to expose the fuses until the circuit is open and no current is passing through them. This desirable relationship is established by providingr the fuse cover 16 with a relatively deep side flange by which it is hinged to the body at 18, 18", and preferably by making it chambered, that is to say, with an interior space which may be occupied, when the cover is closed, by such parts of the fuse or use-holding means as project beyond the limits of the box body proper. wholly at one side of the box, without any part which over-hangs the cover, will satisfactorily cooperate with such a cover because of the depth of the hinged tlange or side wall thereof and because of the considerable lateral movement of such side wall incident to the swinging of the cover on its hinge axis.

-lt will be observed that the flange 1'9 constitutes the laterally movable yportion of the cover means as hereinbcforereferred to. 'lhis interlocking organization ot'cover and side handle is verysimple and effective and easily made and constitutes an important lVhen the switch cover 17 and the fuse cover 16 are both pivoted for lateral movement their pivoted axes maybe coincident and they are so shown; The fuse 'cover 16 may be addition-` ally held in closed position by means of a latch 24. Y

It will be observed thatthe laterally movable portion of the fuse cover means, in this case the flange 19, terminates at a horizontal edge adjacentthe switch opening position of the handle 14 as clearly shown in Fig. 2. As

illustrated the switch opening position of the handle is the lowermost position thereof and the said cover portion terminates with its horizontal bottom edge 19 immediately above the said position of the handle.

It is ordinarily preferable to so-connect or relate the switch cover and the fuse cover means thatthe said fuse cover means is moved to an open position whenever the switch cover is opened t us ensuring the complete opening of the box for convenient inspection of the entire interior thereof by a single opening movement. The necessary connecting and co-relating of the switch cover and the fuse cover means may be variousl effected but when there are provided a switch cover and a fuse cover both hinged lfor sidewise pivotal movement about a common axis 1t 1s convement to so construct the covers that the fuse The crank arm 14 which is located It may be desirable to "so 4construct and arrange theV parts that thel handle, when in switch closing position, serves -not only to 4prevent ope-ning of the fuse cover but also serves to prevent opening ofthe switch cover. In the present case this result is obtained by the overlapping relationship of the fuse cover and switch cover as already described. Ob-

viously when the fuse cover is held in closed position as shown in Fig. 1 the switch cover is also held in closed position.

In order to further facilitate'access to the switches may provide a cover section or inspection door additional to the cover 17 alrcady'described. This door is shown at 22 being hinged to the bottom end wall of the box. The cover section 22 is in effect, merely a part of the corresponding end wall of the box, hinged to form a flap or door and provided with end flanges 23 and otherwise shaped, so that'when it is closed it can be embraced and held closed by the flange o the main switch cover section 17. The two coverl sections 17 and 22 together protect or close that part of the box through .which access can be had to the live or service side switch parts, the section 17 being a propriately proportioned so that it exten( s close enough to lthe switch base to prevent accidental contact by the user with the live parts when the -fusecover is open, and if-need be, so close to the base as'to prevent the insertion of wires into Contact withvsuch parts.- The section 17 is provided with a latch or sealing means 20 so that it and the flap door 22 can be sealed against opening by unauthorized persons, but the section 17 can be closedwhenthe flap door is open. The flap door section 22 serves the two purposes of-enlarging the access to the switch parts which is provided by the sect-ion 17, and it also affords an' inspection opening through which the interior switch mechanism can be observed, when in operation. For this purpose it is necessary, in the form shown, that the main and auxiliary cover sections shall be both closed in order to permit the use of the crank and handle. For example, if the inspection flap or door 22 is opened, as in Fig. 3. and the cover .sections 16 and 17 are then closed, the switch elements can be moved back and forth by the handle andcan at the same time be watched and examined through the inspection opening. The position of the flap door at one end of the box and hence nearer to the back wall of the box body than any of the other sections, makes it possible to sec llO under or back of the switch base, where the switch blades are mounted. I have illustrated only one inspection iap but obviously it can be duplicated at the opposite end', or even at the sides, if desired, so as to provide still greater accessibility to the space behind the base. It is ordinarily not necessary'to protect the load side wire connections 11 from Y attained in the present case Aby duplicating Y the auxiliary cover secion 17 at the opposite end of the box and sealing it in the same way so that the opening of the chambered section will not expose the interior of the box on the load side.

lVhile it is preferred to hinge the two auxiliary cover sections, 17 and 22, in the manner shown in the drawings,.it is obvious that they. can be otherwise arranged so as to perform their principal function, which is to provide a liberal opening and direct access to the live terminals andthe space under the switch base, and preferably by locating such cover sections, or cover means, at right angles to each other and on two adjacent sides of the box so that they open a corner,- rather than a side, of the box. This arrangement of the cover, -whether consisting of separate scc tions asin the present case or otherwise, will be recognized as affording special conveniences quite irrespective oi5 the shape of the fuse cover and its relationto the switch operating handle, as well as of the use to whichv the switch is designed, whether service or individual uses.

Claims:

1. A- fused switch comprising in combination, an inclosing box, fuse contacts in the box, a switch in the box, an openable front cover servmg when closed to prevent access to the switch while permitting access to the fuse contacts, additional frontcover means Y normally serving to preventaccess to the fuse contacts and movable independently of the first said cover to permit such access, the said cover means including a laterally movable portion whieh, wheneverthe first said cover is closed and the said cover means is in access permitting position, projects at one side of the box, and an exterior switch 0pcrating handle having at least a part thereof adjacent the wall ofthe box at the last said lside thereof and movable from switch opening position to switch closing position 1n a vpath which is directly obstructed by the said portion of the fuse cover means when project ing as aforesaid, the said side part of the handle when in switch closing position dition, an inelosing box,

means so as to prevent movement of the said means toaccess permitting position.

2. fused switch comprising in combination,.an inclosing box, an insulating base in the box, fuse receiving contacts-on one face of the base, la switch adjacent another face of the base, an openable front cover serving when closed to prevent access to the switch while permitting access .to the fuse contacts, additional front cover means normally serving to prevent access to the fuse contacts and movable independent-ly of the first said cover to permit such access, the said cover means including a laterally movable portion which, whenever -t-hc first said cover is closed and the said cover means is in access permittiner position, projects at one side of the box, an an exteriorl switch operating handle having at least a part thereof adjacent the wall of the box at the last said side thereof and movable from switch opening position to switch closing position in a path which is directly obstructed by the said portion of the fuse cover means when-projecting as aforesaid, the said side part of the handle when in switch closing position directly obstructing movement of the said laterally movable portion of the fuse cover means so as to prevent movement of the said means to access permitting position.

3. A. fused switch comprising in combinause contacts in the box, a switch in the box, an openable front cover serving when closed to prevent access to the switch while permitting access to the fuse contacts, additional front cover means normally serving to prevent access to the fuse contacts and movable independently ot thc 'first said cover to permit such access, the said cover means including a portion which isv latwhenever the first; saidcover is closed and the said cover means is in access permitting position, projects at one side of the box, and an exterior switch operating handle having at least a part thereof adjacent the wall of the box at the last said side thereof and movable from switch opening position to switch closing position in a path which is directly obstructed by a horizontal edge of the said ortion of the fuse cover means when )rojecting as aforesaid, the said side part o the handle when in an position other than that corresponding to t 1e fully open position of the switch directly obstructing movement of contacts, additional front cover means normally sei-ving to prevent access to the Vfuse contacts, additional front cover` means normally serving to prevent access to the fuse contacts and movable independently of the first said cover to permit such access, the said cover means including a laterally movable portion which, whenever the first said cover is closed and the said cover means is in access permitting position, projects atone side of the box, means serving to cause an opening movement of the said fuse cover means whenever the first said cover is opened, and an exterior switch operating handle having at least a part thereof adjacent the wall of the box at the' last said Side thereof and movable from switch. opening position to switch closing position in a path which is directly obstructed by the said portion of the fuse cover means when projecting asaforesaid, the said side part of the handle when in switch closing position directly obstructing movement of the said laterally movable portion of the fuse cover means so as to prevent movement of the said means to access permitting position.

5. A fused switch c'omprising in combination, an iiiclosing box, fuse contacts in the box, a. switch inthe box, an opcnable front cover serving when closed to prevent access to the switch while permitting access to the fuse contacts, an additional front cover normally serving to prevent access to the fuse contacts and opeuable independently of the lirst said cover to permit such access, the said @over having a portion which, whenever the lirst said cover is closed and the second said cover is open, projects at one side of the box, and an exterior switch operating handle having at least a part thereof adjacent the wall of the box at the last said side thereof and movable from switch opening position to switch closing position in a path which is directly obstructed by the said portion of the .i'nse cover when projecting as aforesaid, the said side part of the handle when in switch closing position directly obstructing movement of the said portion of the fuse cover to prevent movement of the said cover to access permitting position.

G. A fused switch comprising in combinaiimi, an inclosing box, fuse contacts in the box, a switch in the box, an opeiiable front cover serving when closed to prevent access to the switch while permitting access to the fuse contacts, an additional front cover normally serving to prevent access to the fuse contacts and op'enable independently of the first said cover to permit such access, the said cover having a portion which, whenever the first said cover isclosed and the second said cover is open, projects at one side of the-box,and an exterior switclroperating handle having at least a part thereof adjacent the wall of the box at the last said side thereof and movable from switch opening position to switch closing position in a path which is directlyv obstructed by the said portion of the fuse cover when projectinfr as aforesaid, the lsaid side part of the handle when in switch closing position directly obstructing movement of the said portion -of the fuse cover to prevent movement of the said cover to access permitting position.

7. A fused switch comprising in combination, an iiiclosing box, fuse contacts inthe box, a switch in the box, an openable front cover serving when closed to prevent access to the switch while permitting access to the fuse contacts, an additional front cover normally serving to prevent access to the fuse contacts and openable independently of the first said cover to permitsuch access, the said cover having a portion which is moved in parallel- A ism to a projecting position at one side of the box whenever the first said cover is closed and the second said cover is opened, and an exterior switch operating handle having at least a part thereof adjacent the wall of the box at the last said side thereof and movable from switch opening position to switch closing position in a path which is directly obstructed by a horizontal edge of the said portion of the fuse cover when in projecting position as aforesaid, the said side part of the handle when in any position other than that corresponding to the fully open position of the switch directly obstructing movement of the said laterally and parallelly movable portion of the fuse cover to prevent movement of the said cover to access permitting position.

, 8. A fused switch comprising in combination,.an inclosing box, fuse contacts in the box, a switch in the box, an openable front cover serving when closed to prevent access to the switch while permitting access to the fuse contacts, an additional front cover normally serving'to prevent access to the fuse contacts and openable independently of the first said coverl to permit such access, the said cover having a portion which projects at one side of the box whenever the first said cover is closed and the second said cover is open, means serving to canse' an opening movement of the fuse cover means whenever the first said cover means is opened, and an exterior switch operating handle having at least a part thereof adjacent the wall of thc box at the last said side thereof and movable from switch opening position to switch closing position in a path which is directly obstructed by the said portion of the fuse cover when projecting as aforesaid, the said Side part of the handle when in switch closing position directly obstructing movement of the said portion of the fuse cover to prevent movement of the said cover to access permitting position.

9. An externally operated inclosed switch comprisingaboxbodycontaining a switching element, a cover having a relatively 'deep flange or sidewall hinged to a side wall of by o ening the cover,

said body, and an exterior crank arm and handle for operating said switching element journalled to swing at one side of the box adjacent and parallel to said deep fiange when the cover is closed, the said crank arm and handle being adapted to be directly engaged by the flanged side of the cover to .thereby'obstruct cover opening when the circuit is closed. Y

10. An inclosed switch comprising a'box body., a chambered cover havin a side wall hinged to the body, fused switc i mechanism mounted on the box with the fuse or fuses projecting into the cover when closed, and a switch-operating crank arm having a handle journalled to swing entirely at one side of the box adjacent and parallel to said hinged cover side wall, the said handleserving when the switch is closed to directly engage the side wall ot' the cover to obstruct opening of the said cover.

11. An inclosed switch comprising a box body, a cover having a relatively deep side wall hinged to the body, fused switch mechanism in thebox including a fuse exposed a switching element whol y contained within the body of the box and not exposed by opening the cover, and operating means for said element having a side handle crank arm swinging. adjacent and parallel to the dee hinged side wall of the cover to-be engage by the outer face of said wall to obstruct cover opening when the switching element is in its closed position.

12. An inclosed fused switch comprising a box body, a chambered Cover having a side wall hinged to the body, a switch base supported in the body and near the rim thereof, a switching element mounted on the inner side of the base, a fuse mounted on the outer side thereof and projecting into the chamber of the cover, and an external switch-operating crank and handle located wholly at one side of the box body and swinging adjacent and parallel to the hinged cover side wall to obstruct cover opening when the circuit is closed.

13. An inclosed switch comprising a box body containing a switching element and having a flanged cover hinged to its side wall, in combination with a switch-operating means comprising a rod bent to form an interior crank connected to said clement and an exterior crank arm terminating in a handle portion located entirely at one side of the box and swinging adjacent and in a plane parallel to said wall and hinge axis and thereby obstructing opening of the cover when in its circuit closing position.

14. An externally-operated, inclosed switch comprising a box bod a ehambered cover having one of its clianil'ier-forming side walls hinged to the body, a switching element in the box, an o )erating means therefor journalled in the x and having an exterior wall entirely at crank arm and handle swinging adjacent and parallel to said hinged cover side wall when the cover is closedythe last said side wall of the said cover being arranged to encounter the handle-carrying part of said crank arm when the 'latter occupies its switch closing position to obstruct cover opening and the said sidewall serving when the cover is open to encounter the handle carrying part. of the said crank arm to prevent movement thereof f rom switch opening to switch closing position.

" 15. An inclosed fused switch comprising a box bo'dy containing switch mechanism including a switching element and its apurtenant contacts and wire connecting means and a' fuse, a cover section having a deep side wall hinged to the bodyand covering the fuse, a second cover .section for preventing access to the live switch parts, means for sealing the said second section in closed position, and an operatingmeans for said switching element comprising an external crank arm swinging adjacent andparallel to said hinged cover side one side thereof on -thc outer side of the hinge thereof and engaged thereby to obstruct cover openi g and to prevent exposure of the fuse when the circuit is closed.

16. An inclosed fused switch comprising a box body containing switch mechanism including a switching element and its wire connecting means ant a fuse, a primary cover section hinged by a relatively deep side wall to the body and covering the fuse, a second cover section for preventing access to the live switch parts, arranged to be retained in closed position by the closure of the fusecovering section, and an external operating crank arm for said switching element swinging adjacent and parallel to the hinged side wall of said fuse-covering` cover section and entirely at one side thereof to prevent opening of both sections when the switch is closed.

17. An inclosed fused switch comprising a box body, a primary cover hinged thereto, switch mechanism therein having a fuse accessible to the user by opening the cover and including a switching element and'serviceside wire connections which are unexposed and relatively inaccessible on opening sait cover, in com i-nation with an external operating means for said element mounted in the box body and adapted to prevent opening of said cover when in its circuit-closing position. a second cover member adapted to expose. said switching element when the first said cover is open, means whereby the second said member must be closed when the irst said cover is closed, and means inde endent of the first said cover for locking t ie second said cover in closed position.

18. An inclosed fused switch comprising a box body containing switch mechanism having a fuse, a cover adapted to expose the fuse but not the live or service-side parts of the switch mechanism, a second cover means disposed on both sides of a corner of the switch inclosure adapted to be opened to expose said live parts, and a sealing device for the said second cover means.

19. An inclosed fused switch comprising a box body containing switch `mechanism having a fuse, a cover adapted to expose the fuse but not the live or service-side parts,`a second cover means disposed at the corner of the switch inclosure, part thereof being on the front of the inclosure and part at the end thereof and adapted to be opened to expose said-service-side parts, and means for locking the' said second cover means.

20. An inclosed fused switch comprising a box body, a switch base therein having a fuse on its outer side and switch mechanism on its inner side, a cover for exposing the fuse, and another cover normally disposed at an angle to the fuse cover for providing inspection access to the inner side of the switch base.

21. An inclosed fused switch comprising a box body, a switch base therein having a fuse on its outer side and switch mechanism on its inner side, a front cover for exposing the fuse, a crank handle for operating the switch adapted to obstruct opening of said cover, a door in theend wall of the box body adapted to be open when the crank handlel is in its circuit-closing position, and means for sealing said door independently of the fuse cover.

Q2. A fused switch comprising in combination, an inclosing box, fuse contacts in the box, a switch in the box, an openable front cover serving when closed to prevent access to the switch while permitting access-to the fuse contacts, a front cover serving when closed to prevent access to the fuse contacts and openable independently of the first said cover to permit such access, an exterior switch operating handle having at least a part thereof adjacent one side wall of the box, and means associated with the said covers and the said side part of the handle for preventing opening of either cover when thefhandle is in switch closing position, the said means permittingopening of both covers independently of the handle when the handle is in switch opening position.

23. An inclosed fused switch comprising a box body, a switch base therein having a fuse on its outer-side and switch mechanism on its inner side. a cover for exposing the fuse but not the live parts, a crank handle for obstructing opening of such cover when the circuit is closed, and an independent second coverf'adapted to expose said live` a fuse accessible to the user by opening said cover section, a switching element and service-side connection in said body unexposed on opening said cover section, and two other cover sections normally excluding access to said service connections, one of the last said sections being incapable of opening except by openingthe primary section and thepother being adapted to permit inspection of the box interior when said primary section is closed, in combination with an external operating handle for the switching element adapted to obstruct opening of the primary cover section while the circuit is closed.

Q5. An inclosed switch comprising a box body containing switch mechanism including a switching element and its service side wire connections and a fuse, a cover section adapted to expose the fuse, a second cover section preventing access to the service-side parts, a seal for said second section, an external operating` crank arm for said switching element adapted to prevent opening of the fuse section when the circuit is closed, and a hinged inspection door adapted to be locked closed by said second cover section.

26. An inclosed fused switch comprising a box body, a switch base therein having a fuse on its outer side and switch mechanism on its inner side, a cover section adapted to expose the fuse but not the vlive parts of the switch mechanism, a second cover section adapted to bridge and close the space between said base and one end of the boxbody, both said cover sections being hinged to the box body, and means to prevent the opening of either cover section while the circuit is closed.

27. An inclosed fused switch comprising a box body, a switch base therein having a :fuse on its outer side and switch mechanism and wire connections on its other sides, a chambered cover section adapted to expose the fuse, a relatively shallow second cover section adapted to expose the wire connections, both sections being hinged to the same wall of the box body, and means to prevent opening of the fuse cover section while the circuitis closed. i

In testimony whereof, I have signed this specification.

JOSEPH SACHS.

crnriricfrrr or coRREorroN.

Patent No. 1,721,494. Granted July it, i929, i@

JOSEPH SACHS.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Fage 5, lines l to 3, claim 4, strike out the words and comma "additional front cover means normally serving to prevent access to the fuse contaots,"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record 0f the case in the Patent Office.

Signed and sealed this 29th day oi October, A. D. 1929.

- M. J. Moore, `(Seal) Acting Commissioner of Patents. 

